Many urban areas have experienced a significant increase in traffic in many areas in recent years. The traffic generally includes automobiles, but can also include larger vehicles such as trucks and other vehicles which create a great deal of noise such as motorcycles, and the like. If the trucks are large, and the vehicular traffic heavy, anyone living adjacent to a traffic bearing highway will be significantly impacted. In some instances, the noise is so great that normal conversation and sleep is affected, if not totally prohibited.
Recognizing this problem, most highway commissions have noise level standards that include decibel as well as range criteria. If the noise is above a certain level, then many laws and regulations require sound-barrier walls to be erected adjacent to the highway. These sound-barrier walls must, of course, be effective in absorbing sound, but must also be aesthetically pleasing. These walls can be extremely expensive, therefore, an additional requirement is that they be as economical as possible. Economy in such walls is found not only in the manufacture thereof, but in the shipping, storing, erection, use and durability of the wall.
The art has attempted to meet these needs with various sound-barrier walls. While the walls known to the inventors are somewhat successful in some areas, the inventors are not aware of any such sound-barrier wall that meets all the needs of modern highway construction while being economical as that term is used herein.
For example, many presently-known sound-barrier walls do not adequately absorb all noise, especially in the frequencies existing adjacent to a highway. Therefore, such walls may prove to be inadequate after only a short time, especially if, after the wall is erected, the traffic pattern of the highway changes to increase the load of heavy trucks. This may even require replacement of some of the walls. Such replacement is obviously uneconomical.
The inventors have also found that present sound-barrier walls suffer further economic drawbacks due to their low durability, lack of weather resistance and difficulty in storage and erection. For example, some sound-barrier walls presently known to the inventors may fail after only a few freeze-thaw cycles, or do not have good drainage characteristics, or require special, and expensive, shipping procedures, or require a great deal of labor to erect. Any, and all, of these drawbacks result in economic disadvantages to a sound-barrier wall.
Therefore, there is a need for a sound-barrier wall that is efficient in absorbing the noise that will be most prevalent while still being durable, yet is economical, including being weather resistant and environmentally beneficial.
In modern society, even with noise absorption from sound barrier walls, and the like, it is beneficial to have further sound absorption carried out in the buildings and other static structures enclosing people. Therefore, there is a need for a building panel that can be used in a static structure, such as a building, which can absorb sound.